Electrically operated pump



R. L. KENTl-Tl AL 1,987,257

ELECTRICALLY OPERATED PUMP Filed July 24, 1953 Jim. -s, 1935;

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reamed Jan. a, 1935 1,987,257 V ELECTBICALLY OPERATED PUMP Raymond Leslie Kent and John Neville Morris.

Adderley Park, Birmingham, England Application July 24, 1933, Serial No. 881,998 In Great Britain October 19, 1932 3 Claims. (Cl. 175-844) This invention has for its object to provide an improved electrically operated pump adapted more particularly tor supplying petrol or the like to the carburettor or an internal combustion en- The invention comprises the combination with the core and hollow cylindrical pole piece of an electromagnet, 01' an armature in the form or an irm disc, and radially disposed means abutting at their opposite ends against the cylindrical pole piece and armature ior holding the latter in its central position during its movement under the action of the magnetic flux.

Also the invention comprises an armature disc formed with a central cavity at the part which eo-operltes with the adjacent end or the magnet core, the cylindrical pole piece being formed with an annular step for co-operating with the periphery or the disc.

Further the invention comprises a pump having the-combination and arrangement 01 parts here-' inatter described.

In the accompanying sheet of explanatory drawingz- Figure 1 is a longitudinal section a petrol pump constructed in accordance with this invention and adapted for use on a motor vehicle.

Figure 2 is a cross section on the line l-2 l'lgure 1, and Figure 3 is a cross section on the line 3-4 Figure 1.

In the construction oi. a petrol pump as shown, we employ an electromagnet the winding a or which is carried on a hollow iron core I), and is surrounded by a cylindrical iron pole piece 0. At the open end oi the pole piece isarranged an 'armaturedintheiormotadiscwhichwillbe described more iully later. On the'closed end e or the cylindrical pole piece is carried a contact breaker 0! any convenient form, consisting in part of a toggle mechanism for producing quick action of the movable contact member. In the example illustrated the said mechanism comprises a pair or levers. One of the levers comprises a pair of rigidly interconnected side members I, f, and the other comprises a pair 01 rigidly interconnected side members a. 0, situated between the members 1, I. The two levers are pivoted at one end at h, and at their other ends are interconnected by a coil spring i. The lever formed by'the parts I. f carries a contact piece :i which can co-operate with another contact piece k carried on a resilient blade I. j, 1:, control the electric circuit containing the winding a of the electromagnet in the usual way.

'lheleveriormedbythepartsmgisconnected The contact pieces,

to and actuated by a rod m which passes through the core b and is secured to the armature d. In the position shown in Figure 1 the parts 7', k are in contact and the circuit is closed. When by means 0! the rod m the parts 9 are moved to the left, the first effect is to strain the spring 2'. When the parts g reach the other side of the parts i the latter are moved to the right by the said spring and the contacts 7, k are thereby separatedand the circuit is opened. When the rod m moves to the right, the parts 9 again move relatively to the parts I causing the spring to be strained, until a certain position is passed, and then the spring returns the parts ,1 to the initial position causing the circuit to be re-closed. The contact breaker may be enclosed by any convenient cover n.

At the open end of the cylindrical pole piece 0' is providedv a flange 0 on which is carried a hollow member p containing the inlet valve q and the outlet valve 1'. One side of this member p is shaped to form a shallow pump chamber s. The chamber s is bounded on one side by the wall t, and at the other side it is bounded by a flexible diaphragm it which separates the armature disc (I from the pump chamber. The diaphragm is made from any convenient impervious flexible thin material, and is secured to the armature disc by a plate 13 on the rod m. On the opposite side of the wall t to the pump chamber, there is formed in the hollow body p a chamber 11 which is closed by a removable cover w. Petrol is admitted to the chamber 22 through an inlet connection 2:, and before it can gain access to the inlet valve q it must pass through the filter 11. After passing the inlet valve, which is held on its seating by a spring 2, the petrol can flow through an aperture 2 in the wall t to the pump chamber. From the pump chamber the petrol passes again through the aperture 2, and thence through the outlet valve 1', to the outlet connection 3. Dislodgment of the valve 1' by excessive movement is prevented by a spring ring 4 secured to the part 5 which carries the valve 1'.

In order to obtain as uniform a pull as possible on the armature d when the magnet is excited, we form an annular step or shoulder '1 around the interior of the openend of the cylindrical pole piece 0 so as to concentrate the flux in the adjacent edge of the armature, and at the centre of the armature a shallow recess 8 is formed to receive the adjacent end of the core b. At first the flux is concentrated in the gaps formed by the outer edge of the armature and the shoulder on the surrounding pole piece, and by the edge of the core and the edge of the recess in the armature. Later the armature passes over the end of the core and finally the pull is exerted mainly by the flux in the gap between the flat end of the core and the base of the aforesaid recess. By so shaping the parts we are able to avoid the usual large increase in pull which accompanies reduction of air gap, and obtain a suillciently uniform pull throughout the movement of the armature.

p The suction stroke or the pump is eflected by the movement of vthe armature under the influence of the magnetic pull, and this movement is effected quickly. As soon as this stroke is completed the contact breaker is actuated 101' opening the inagnet circuit, and the delivery stroke'is effected by a spring 9 situated on the magnet side of the armature. At the end ofthe delivery stroke the contact breaker closes, and the cycle of operations is repeated.

Due to the fact that the air gap between the periphery of the armature d and the cylindrical pole piece c is small, a slight inaccuracy in the centering of the armature results in' a strong side pull which may interfere with the proper action of the pump. To neutralize this condition we arrange between a shoulder 10 at the pump side f of the armature and a shoulder. 11 in thesurrounding pole piece a plurality oi. radial thrust pieces. These may conveniently take the form of discs or thin rollers 12 having spherical peripheries so that each can rock about its points of contact with the armature and outer pole piece. The roller-form of these thrust pieces isv convenient because of ease and simplicity of manufacture, but if desired they may consist of quadrilateral pieces having straight sides and curved ends. In the position of the armature shown in Figure 1 the thrust pieces'are slightly inclined to the plane of the armature, and they assume a position more nearly corresponding to the plane of the armature as the latter moves to the leit, so that they exert a toggle like action which eilectually prevents lateral displacement of the armature.

By this invention we are able to provide an inexpensive and reliable pump suitable for use as a i'uel pump or for like purposes in a very simple and convenient manner. The invention lsgnot limited to the example describedas subordinate details can be varied to suit diflerent requirements. 7 V

Having thus described our invention what we claim as new and desire to secure by Letters Patcut is: i

1. In an electromagnetic motor; the combination with the core and hollow cylindrical pole piece of an electromagnet, of an armature in the form of an iron disc, and radially disposed means abutting at their opposite ends against the cylindrical pole piece and armature for holding the latter in its central position during its movement' under the action of the magnetic flux; substan-- tially as described. 2. In an electromagnetic motor, the combination of an electromagnet core, a hollow cylindrical pole surrounding thecore, can armature disc co-operating with one end of the said core and pole piece, a shoulder on each of the disc and pole piece, and roller like abutment pieces situated between the said shoulders, the abut ment pieces being arranged and adapted to operate substantially as described.

3. An electromagnetic motor as in claim 1, in

which the disc is formed with a central cavity at the part which co-operates with the core, whilst.

the cylindrical pole piece is formed with an annular step for co-operating with the periphery of the disc, substantially as described.

. RAYMOND LESLIE KENT.

JOHN [NEVILLE MORRIS. 

